[vintagemilano]

I didn’t see a bodywork technical forum so I will just put this here until someone thinks it should be moved.
I have some second hand Shankle fibreglass bumpers for the 77 spider. The mounting studs were in rough shape. They weren’t really studs at all but just bolt heads glued into a quarter inch fibreglass layer. Definitely not engineered to ever be removed after install.
Has anyone tackled this already or know of a product that would work? I big metric rivnut or?
The fibreglass is very thin, only a quarter inch tops, not nearly enough for a real insert.
Thank you,

 

[bianchi2]

. these are elevator bolts, you can get them on line , cheap ( save your money for gas to drive your car ) sand the heads to get them rough,, clean the area well with acetone then epoxy them to were you want then take some acetone again clean the area really really well , ( that fingernail polish remover will work just fine).. then get a pint of fiberglass epoxy its a 2 part system... then but cuts squares out of the fiberglass ' cloth ' not matt.. cut about 4 sheets of cloth to the size that you want then 4 little holes to clear the studs ( cover the studs with those vacumn hose ends ) wet the cloth , slip it over the repair,, massage the both to remove any air pockets.. you will see them,, they look white and compaired to a dark wet look.. once you have the 1 st layer of glass on ( as the layers go one, make each layer 10 mm bigger than the one you just put down, lay the 2nd layer of glass on. massage that into the wet epoxy( add epoxy as needed ),, massage in ,add 3rd layer, , and repete what you did on the 2nd layer add layers untill done,,,, this will make a strong finish

and from now one use antiseize on every bolt that you find.. here's a winter project for you,, remove your front bumper,, clean the threads.. anitseize them put the bumper back one.. just slowly go around your car,, look for any bolt or nut that could use a nice coat of anti seize on the threads

 

[bianchi2]

......

 

[garwood1]

Those must be much lighter than the originals...I guess the trade-off is lack of impact resistance.

 

[bianchi2]

what impact resistance?

 

[ossodiseppia]

Those must be much lighter than the originals...I guess the trade-off is lack of impact resistance.

Yes, they are much lighter. I don't think they are hollow. I seem to remember them described as having some sort of honey comb inside.

 

[vintagemilano]

Thank you for the ideas.

They are hollow, there is a bit of a box section right where the mounts are.

 

[vintagemilano]

Definitely lighter, somewhere close to 8 pounds.

 

[bianchi2]

is that the same ' fish ' scale i use..? i know my 14 inch trout i caught weighed 5 pounds... my ' fish ' scale said so